Various fluids can actuate a Fluidic Elastomer Actuator (FEA) as long as fluid can pressurize an internal chamber of an FEA. The choice of the pressurizing fluid significantly affects the FEA characteristics. However, few studies have quantitatively evaluated the differences in FEA characteristics with different pressurizing fluids. Especially to our best knowledge, no research has investigated such differences for bending-type FEAs. In this study, we experimentally evaluated the characteristic differences between pneumatically-actuated and hydraulically-actuated BFEA. Referring to previous studies, we set four evaluation targets as follows. Actuation speed, force generation, time-domain control characteristics, and static and dynamic positioning control characteristics. The results show significant characteristic differences. Furthermore, the results suggest that these differences are mainly due to compressibility, viscosity, and stiffness difference between air and water.